1. Field of the Invention
The invention provides compounds, pharmaceutical compositions comprising such compounds and methods of using such compounds to treat or prevent diseases or disorders associated with the activity of liver X receptors (LXRs).
2. Background
Liver X receptors (LXRs), LXRα and LXRβ, are nuclear receptors that regulate the metabolism of several important lipids, including cholesterol and bile acids. While LXRβ is expressed ubiquitously in the body, LXRα is expressed in the liver and to a smaller degree in the kidneys, small intestine, adipose tissue, spleen and adrenal glands.
LXRs bind to the ATP binding cassette transporter-1 (ABCA1) promoter and increase expression of the gene to produce ABCA1 protein. ABCA1 is a membrane bound transport protein that is involved in the regulation of cholesterol efflux from extra-hepatic cells onto nascent high-density lipoprotein (HDL) particles. Mutations in the ABCA1 gene result in low levels of HDL and an accompanying increased risk of cardiovascular diseases such as atherosclerosis, myocardial infarction and ischemic stroke. LXRα and β agonists have been shown to increase ABCA1 gene expression thereby increasing HDL cholesterol and, as a consequence, decreasing both the net absorption of cholesterol and the risk of cardiovascular disease. LXR agonists also upregulate macrophage expression of apolipoprotein E (apoE) and ABCG1, both of which contribute to the efflux of cellular cholesterol. By stimulating macrophage cholesterol efflux through upregulation of ABCA1, ABCG1 and/or apoE expression, as well as increasing the expression of other target genes including cholesterol ester transfer protein and lipoprotein lipase, LXR agonists influence plasma lipoproteins.
The novel compounds of this invention modulate the activity of LXRs and are, therefore, expected to be useful in the treatment of LXR-associated diseases such as cardiovascular diseases, inflammation and disorders of glucose metabolism such as insulin resistance and obesity.